CN110190278B

CN110190278B - Nickel-cobalt lithium aluminate anode material and preparation method and application thereof

Info

Publication number: CN110190278B
Application number: CN201910414990.6A
Authority: CN
Inventors: 杨亿华; 钟毅; 王海涛
Original assignee: Hunan Jinfuli New Energy Co ltd
Current assignee: Hunan Jinfuli New Energy Co ltd
Priority date: 2019-05-17
Filing date: 2019-05-17
Publication date: 2020-12-01
Anticipated expiration: 2039-05-17
Also published as: CN110190278A

Abstract

The invention provides a nickel cobalt lithium aluminate anode material which is characterized by comprising a basic anode materialAnd a lithium-containing coating thin layer coated on the surface of the basic positive electrode material, wherein the chemical formula of the nickel-cobalt lithium aluminate positive electrode material is Li_xNi_aCo_bAl_cO₂Wherein: x is more than or equal to 0.98 and less than or equal to 1.05, a is more than or equal to 0.70 and less than or equal to 0.92, b is more than or equal to 0.02 and less than or equal to 0.17, c is more than or equal to 0.01 and less than or equal to 0.08, and a + b + c is 0.73-1.17. The nickel-cobalt lithium aluminate anode material effectively inhibits the dissolution of structural metal nickel and other elements in the anode material, and improves the high temperature and safety performance of the lithium ion battery prepared from the nickel-cobalt lithium aluminate material. The invention also provides a preparation method for the nickel cobalt lithium aluminate anode material. Meanwhile, the invention also provides a lithium ion battery prepared by the nickel cobalt lithium aluminate material and application thereof.

Description

Nickel-cobalt lithium aluminate anode material and preparation method and application thereof

Technical Field

The invention relates to the field of lithium battery cathode materials, in particular to a cathode material developed for improving the high-temperature cycle performance of a nickel-cobalt lithium aluminate material, and a preparation method and application thereof.

Background

Along with the rise of smart phones and new energy vehicles in recent years, more and more devices show the trend of electromotion and become data acquisition points and integration points of big data, the Internet of things and the like. The power consumption of mobile equipment is higher and higher, when energy is provided for a mobile terminal, when a lithium ion battery is under the conditions of quick charge, quick discharge and high-temperature use, the internal stress of the material body structure is increased due to the quick insertion/extraction of lithium ions, and meanwhile, due to the fact that the ion radii of the lithium ions, nickel/cobalt/manganese ions and the like are close, the lithium ions are mixed and arranged in a layered structure under the driving of thermodynamics, so that the cycle and use reversibility of the lithium battery is reduced, particularly, ions of different valence states of nickel in a ternary material are easy to extract and enter a lithium ion layer, so that the mixing and arrangement are caused, and the cycle performance is sharply reduced.

In addition, with the application of lithium ion batteries becoming more and more extensive, cobalt resources are concentrated and limited as a strategic metal supply, so that the lithium ion battery positive electrode material has a tendency of 'cobalt removal/cobalt-free', that is, the cobalt content in the lithium ion positive electrode material is lower and lower, even cobalt-free positive electrode materials such as lithium manganate and lithium iron phosphate are adopted, but in terms of energy density and platform operating voltage, materials with high nickel content and low cobalt content will be the mainstream positive electrode materials of future lithium ion power batteries, and NCM622, NCM811, NCA and the like with higher market call sound at present may become the main positive electrode materials in the future, and the molar content of nickel in the materials is usually more than 0.5mo, and the corresponding cobalt content is lower, so the materials are also generally called as high nickel ternary materials.

The main problems that the application of the nickel-cobalt lithium aluminate material is limited at present are that the stability of the preparation of the nickel-cobalt lithium aluminate precursor is poor, the requirements of the production of the nickel-cobalt lithium aluminate material and the front-end working procedures of the corresponding lithium battery on the control of the moisture content are high, and the high-temperature cycle performance and the safety performance of the lithium ion battery prepared from the high-nickel material need to be further improved. The electrochemical performance is related to the transition layer and dissolution of nickel in the high-nickel material. Research shows that after the lithium nickel cobalt aluminate lithium ion battery is cycled for about 100 weeks, in addition to apparent observation of faster capacity attenuation, nickel element enrichment of more than 1000ppm appears on a negative electrode plate of the lithium battery after the cycle of disassembly, and along with the cycle, the content of nickel on the negative electrode plate can be gradually increased to more than 4000ppm, which shows that the precipitation of nickel is still continuously carried out, and metal ions such as cobalt/manganese and the like can also appear on the negative electrode plate besides the nickel element. Therefore, it is reasonable to believe that the deterioration of the cycle performance of the lithium ion battery prepared from the high-nickel material is positively correlated with the dissolution of the structural element in the positive electrode material of the lithium ion battery, for example, the effective inhibition of the dissolution of the structural nickel in the positive electrode material is an effective way to overcome the problem of the high-nickel lithium ion battery, and an effective solution needs to be explored in material preparation.

Chinese patent CN201110222403.7 discloses a method for preparing lithium ion battery anode material doped with aluminum by a solid phase method, which comprises the following steps of preparing a nickel, cobalt and/or manganese hydroxide precursor by controlling certain reaction conditions, uniformly mixing the obtained precursor with lithium salt and a nanoscale aluminum compound, carrying out high-temperature treatment for a certain time in air or oxygen atmosphere, cooling and crushing to obtain the solid phase method doped aluminum-coated lithium ion battery anode material.

Chinese patent CN201310107255.3 discloses a preparation method of a multi-element anode material, which prepares a multi-element material with low alkali content and excellent comprehensive performance through excellent process control, and then prepares the final multi-element NCM622 type anode material through doping and coating means. The anode material prepared by the method has excellent energy density and safety performance.

The above patents and documents relate to the preparation/modification and application of high nickel materials, but are different from the technical solution and solution of the present invention.

Disclosure of Invention

The problems of the prior art solved by the invention are as follows: the lithium ion battery prepared by the existing nickel-cobalt lithium aluminate high-nickel ternary cathode material has poor high-temperature cycle performance, poor safety performance and the like due to dissolution of structural metal ions, and simultaneously, the technical problems that primary particles in nickel-cobalt lithium aluminate high-nickel ternary material particles are small in particle size, large in specific surface area and difficult to repair surface defects are solved.

After the intensive research, the inventor of the invention finds that the nickel-cobalt-aluminum material body has poor ionic conductivity, obvious ionic conductivity 'Gap' exists between the material body and an organic electrolyte after a lithium ion battery is prepared, and then creatively and uniformly permeates a transition layer friendly to a high-nickel ternary material and an electrolyte organic solvent on the surface of a nickel-cobalt-lithium aluminate high-nickel semi-finished product material, wherein the transition layer contains an ionic conductor type lithium-containing compound of metals such as aluminum, titanium, magnesium and the like, so that the defects of high-temperature cycle, poor safety and the like of the lithium ion battery prepared from the nickel-cobalt-lithium aluminate anode material are overcome initially due to the fact that the ionic conductivity of the material body is low in the use process of the nickel-cobalt-lithium aluminate anode material, and a new technical scheme is provided for popularization and use of the nickel-cobalt-lithium aluminate material.

Specifically, the invention provides the following technical scheme:

the invention provides a nickel cobalt lithium aluminate anode material which is characterized by comprising a basic anode material and a lithium-containing coating thin layer coated on the surface of the basic anode material, wherein the chemical formula of the nickel cobalt lithium aluminate anode material is Li_xNi_aCo_bAl_cO₂Wherein: x is more than or equal to 0.98 and less than or equal to 1.05, a is more than or equal to 0.70 and less than or equal to 0.92, and 0.02≤b≤0.17，0.01≤c≤0.08，a+b+c＝0.73-1.17。

Preferably, the nickel cobalt lithium aluminate cathode material has a chemical formula of Li_xNi_aCo_bAl_cO₂Wherein: x is more than or equal to 0.98 and less than or equal to 1.02, a is more than or equal to 0.80 and less than or equal to 0.82, b is more than or equal to 0.15 and less than or equal to 0.17, c is more than or equal to 0.01 and less than or equal to 0.05, and a + b + c is 1.0-1.03.

Preferably, the nickel-cobalt lithium aluminate cathode material, wherein the lithium-containing clad thin layer is selected from a lithium compound layer containing one or more of group IIA, IIIA, IIIB, VIB and VIII metals.

Preferably, the nickel-cobalt lithium aluminate positive electrode material, wherein the lithium-containing clad thin layer is selected from a lithium compound layer containing one or more of magnesium, titanium, aluminum, cobalt, yttrium, zirconium, cerium, lanthanum and hafnium, preferably from a lithium compound layer containing one or more of magnesium, titanium, aluminum and yttrium.

Preferably, the nickel cobalt lithium aluminate cathode material, wherein the particle size (D) of the nickel cobalt lithium aluminate cathode material_v50)7-14 μm, preferably 7.5-13 μm; the specific surface area of the nickel cobalt lithium aluminate anode material is 0.3-1.7m²Per g, preferably 1.2 to 1.7m²/g。

Preferably, the lithium nickel cobalt aluminate positive electrode material, wherein the mass percentage of the lithium-containing coating thin layer relative to the basic positive electrode material is 0.01wt% -0.50wt%, and preferably 0.01wt% -0.30 wt%.

The invention also provides a preparation method of the nickel cobalt lithium aluminate anode material, which is characterized by comprising the following steps:

step 1: mixing a nickel-cobalt-aluminum precursor, a lithium source compound and an auxiliary agent, and performing heat treatment to obtain the basic positive electrode material;

step 2: and (2) mixing the basic anode material with the unreacted lithium source compound and the IIA, IIIA, IIIB, VIB and VIII group metal compounds in the step (1), and performing heat treatment to obtain the nickel-cobalt lithium aluminate anode material, wherein the nickel-cobalt lithium aluminate anode material comprises the basic anode material and a lithium-containing coating thin layer coated on the surface of the basic anode material.

Preferably, in the preparation method, the precursor in step 1 is hydroxide and/or oxide containing nickel, cobalt and aluminum elements.

Preferably, in the preparation method, the lithium source compound in step 1 is one or more selected from lithium carbonate, lithium hydroxide monohydrate, lithium hydroxide, lithium acetate, lithium nitrate, lithium fluoride, lithium tert-butoxide, lithium citrate, and lithium oxalate.

Preferably, in the preparation method, the auxiliary in step 1 is one or more of an ester, a salt or a hydroxide containing lithium, magnesium, titanium, cobalt, yttrium, zirconium, cerium and aluminum.

Preferably, in the preparation method, the percentage content of the mass of the auxiliary agent in the step 1 to the total mass of the nickel-cobalt-aluminum precursor and the lithium source compound is 0.03wt% to 0.6 wt%.

Preferably, in the preparation method, the group IIA, IIIA, IIIB, VIB, VIII metal compound in step 2 is selected from one or more of oxides, salts, or hydroxides of magnesium, titanium, cobalt, yttrium, zirconium, cerium, aluminum, lanthanum, and hafnium.

Preferably, in the preparation method, the content of the unreacted lithium source compound in the step 1 in the step 2 is 0.09wt% to 0.55wt%, and preferably 0.1wt% to 0.4wt%, based on the mass of the lithium source compound in the step 1.

Preferably, in the preparation method, the mixing equipment in step 1 and step 2 is one or more selected from a kneader, a fusion machine, a rake mixer and a coulter mixer.

Preferably, the preparation method, wherein the temperature of the heat treatment in the step 1 is 200-860 ℃, preferably 400-800 ℃; the heat treatment time is 5-20h, preferably 8-16 h;

further preferably, the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere, and the volume content of oxygen is 40-95%, preferably 45-70%; air flow rate of 200-600Nm³Perh, preferably 200-400Nm³/h。

Preferably, the preparation method, wherein the temperature of the heat treatment in the step 2 is 700-880 ℃; the heat treatment time is 8-10 h;

further preferably, the atmosphere of the heat treatment in the step 2 is oxygen-enriched atmosphere, and the volume content of oxygen is 60-95%, preferably 70-90%; air flow rate of 300-600Nm³Perh, preferably 350-600Nm³/h。

The invention also provides a lithium ion battery anode material, wherein the lithium ion battery anode material is prepared by the preparation method.

The invention also provides a lithium ion battery anode, wherein the lithium ion battery anode is prepared from the lithium ion battery anode material and an aluminum foil.

The invention also provides a lithium ion battery, which contains the lithium ion battery anode material or the lithium ion battery anode.

Preferably, the lithium ion battery has a reversible capacity retention rate and/or a recovery capacity of 85% or more, preferably 90% or more, after a high-temperature cycle test.

The invention also provides an application of the anode material or the lithium ion battery anode or the lithium ion battery in the field of lithium battery energy.

The lithium nickel cobalt lithium aluminate anode material is permeated to form a uniform thin layer coating material to form an ion-conducting transition layer friendly to the lithium nickel cobalt lithium aluminate material and electrolyte, so that the dissolution of structural metal can be effectively solved.

The beneficial effects obtained by the invention are as follows: the nickel-cobalt lithium aluminate anode material effectively inhibits the dissolution of structural metal elements such as nickel, cobalt, aluminum and the like in the anode material, and improves the high temperature and safety performance of a lithium ion battery prepared from the nickel-cobalt lithium aluminate material. Meanwhile, the invention also provides a lithium ion battery prepared by the nickel cobalt lithium aluminate material prepared by the method and the beneficial effects of the application of the lithium ion battery.

Drawings

FIG. 1-a is a Scanning Electron Microscope (SEM) image of example 5 at a magnification of 100000.

Fig. 1-b is a Scanning Electron Microscope (SEM) image of comparative example 2, wherein the magnification is 100000 times.

FIG. 2 shows the results of the high temperature cycle tests of examples 1 and 6 and comparative examples 1 and 3.

FIG. 3 shows the results of the nail penetration test in examples 1 and 6 and comparative examples 1 and 3.

Detailed Description

The invention provides a nickel cobalt lithium aluminate anode material which is characterized by comprising a basic anode material and a lithium-containing coating thin layer coated on the surface of the basic anode material, wherein the chemical formula of the nickel cobalt lithium aluminate anode material is Li_xNi_aCo_bAl_cO₂Wherein: x is more than or equal to 0.98 and less than or equal to 1.05, a is more than or equal to 0.70 and less than or equal to 0.92, b is more than or equal to 0.02 and less than or equal to 0.17, c is more than or equal to 0.01 and less than or equal to 0.08, and a + b + c is 0.73-1.17.

Preferably, in the preparation method, in step 1, a cyclone vortex pulverizer with a protective gas nitrogen source is used for pulverizing the product after the first sintering, so as to obtain a semi-finished product of the first sintering, namely the basic cathode material. Preferably, the humidity of the nitrogen of the controlled circulation protective gas is less than or equal to 2 percent.

Preferably, in the preparation method, in the step 2, a cyclone vortex pulverizer with a protective gas nitrogen source is used for pulverizing the product after the first sintering, so as to obtain the nickel cobalt lithium aluminate cathode material. Preferably, the humidity of the nitrogen of the controlled circulation protective gas is less than or equal to 2 percent.

A stable lithium compound layer containing aluminum, titanium, magnesium and other metals is generated by in-situ permeation on the surface of a semi-finished product particle of the nickel-cobalt lithium aluminate anode material and sintering, so that the high-temperature cycle and safety performance of a lithium ion battery prepared from the nickel-cobalt lithium aluminate material are improved.

The cathode material, the preparation method and the application thereof are illustrated by specific examples.

The reagents and instrument sources used in the following examples are shown in tables 1 and 2.

TABLE 1 information Table of reagents used in examples

TABLE 2 Equipment information List used in the examples

Example 1

Step 1: selecting 200L of fusion machine, starting stirring (500rpm), and adding 100kg of nickel-cobalt-aluminum precursor (Ni) under the condition of stirring_0.81Co_0.15Al_0.05(OH)₂) And then 46.6kg of lithium hydroxide monohydrate powder is weighed and added into a fusion machine, 38.3kg of deionized water and 0.057kg of basic cobalt carbonate (the cobalt content is about 300ppm based on the finished product) are added according to the solid content of 80 wt% under the condition of stirring, the speed is further reduced (50rpm) after the stirring is carried out for 2 hours, the stirring is carried out for 20 minutes, and the discharging is carried out to form a paste material for later use.

A24 m ventilated roller kiln is adopted. Setting the temperature of the heating zone at 200 deg.C, introducing oxygen-enriched air (oxygen content volume ratio of 45%, gas input amount of 400 Nm)³H) loading the pasty material into a ceramic sagger for primary sintering, wherein the sintering time is 15h, isolating the material from air, cooling to normal temperature, weighing the weight of the material in and out, and counting the loss on ignition (the ratio of the mass difference of the powder obtained by primary sintering to the mass of the powder obtained by primary sintering) to be 32.8%. And then crushing by using a cyclone vortex crusher with a protective gas nitrogen source, wherein the humidity of the circulating protective gas nitrogen is controlled to be less than or equal to 2% during crushing, and a first sintered semi-finished product, namely the basic anode material, is obtained.

Step 2: and adding the semi-finished product into the fusion machine again, adding 0.05kg of nano titanium dioxide (the titanium content is about 300ppm according to the finished product), 0.13kg of yttrium nitrate hexahydrate (the yttrium content is about 300ppm according to the finished product) and 0.124kg of magnesium acetate (the magnesium content is about 200ppm according to the finished product), taking out the powder after full dispersion, filling the powder into a ceramic sagger, and adopting a ventilating 24m roller kiln. Setting the temperature of the heating zone at 700 deg.C, and introducing oxygen-enriched air (oxygen content volume ratio of 70%, gas input amount of 300 Nm)³H), the sintering time is 8h, the materials are isolated from air and cooled to normal temperature, the weight of the materials entering and exiting is weighed, the ignition loss rate (the ratio of the mass difference of the powder obtained by the second sintering to the mass of the powder obtained by the second sintering) is calculated to be 2.1%, and then a nitrogen source with protective gas is usedThe cyclone vortex pulverizer pulverizes, controls the humidity of the circulating nitrogen gas within 2% or less during pulverizing, namely coats a layer of lithium compound containing titanium, yttrium and magnesium on the surface of the basic anode material, and finally obtains the nickel-cobalt lithium aluminate anode material with the granularity (D)_v50) 9.0 μm, a specific surface area of 1.4m²/g。

The ICP is used for carrying out quantitative analysis on the elements of the nickel cobalt lithium aluminate anode material, and the structural formula is as follows: li_0.98Ni_0.81Co_0.15Al_0.05O₂The mass percentage of the lithium-containing thin-layer coating material relative to the basic anode material is 0.03 wt%.

Example 2

Step 1: A200L coulter type mixer is selected, stirring is started (the rotating speed of a main shaft is 130rpm, the rotating speed of a side cutter is 1400rpm, the stirring time is 50min), and 100kg of nickel-cobalt-aluminum precursor (Ni) is added under the stirring condition_0.80Co_0.15Al_0.05(OH)₂) Then 42.5kg of lithium carbonate powder is weighed and added into a coulter type mixer, after stirring and dispersing for 2h, 3.73kg of titanate auxiliary agent with the content of 20% (industrial grade, purity is 98.5%, content is about 1000ppm of titanium in terms of finished product) is added, stirring is continued for 2h, then speed is further reduced (main shaft rotation speed is 50rpm, side cutter rotation speed is 1300rpm), stirring is carried out for 6h, and paste-shaped materials are formed for standby.

A24 m ventilated roller kiln is adopted. Setting the temperature of the heating zone at 500 deg.C, introducing oxygen-enriched air (oxygen content volume ratio of 65%, gas input amount of 400 Nm)³And h) putting the paste material into a ceramic sagger for primary sintering for 16h, cooling the material to normal temperature in an air-isolated mode, weighing the weight of the material in and out, and counting the loss on ignition to be 27.3%. And then crushing by using a cyclone vortex crusher with a protective gas nitrogen source, wherein the humidity of the environmental circulating protective gas nitrogen is controlled to be less than or equal to 2% during crushing, and a first sintered semi-finished product, namely the basic anode material, is obtained.

Step 2: adding the semi-finished product into a coulter type mixer again, adding 0.34kg of magnesium nitrate hexahydrate (magnesium content is about 300ppm based on the finished product) dissolved by deionized water, and fully dispersing (main shaft rotation speed 130rpm, side cutter rotation speed 1500rpm, stirring time 50min)The powder is taken out and put into a ceramic sagger, and a roller kiln with 24m ventilation is adopted. Setting the temperature of the heating zone to 880 ℃, and introducing oxygen-enriched air (oxygen content volume ratio is 70%, gas input is 600 Nm)³And h) filling the first sintering semi-finished powder into a ceramic bowl for sintering, wherein the sintering time is 8h, cooling the materials to normal temperature in an air-isolated mode, weighing the weight of the materials in and out, and counting the loss on ignition to be 5.1%. Then crushing by a cyclone vortex crusher with a protective gas nitrogen source, controlling the humidity of air circulation nitrogen within 2% or less during crushing, namely coating a magnesium-containing lithium compound layer on the surface of the basic anode material to finally obtain the nickel-cobalt lithium aluminate anode material with the granularity (D)_v50) 8.5 μm, a specific surface area of 1.41m²/g。

The ICP is used for carrying out quantitative analysis on the elements of the nickel cobalt lithium aluminate anode material, and the structural formula is as follows: li_1.01Ni_0.81Co_0.15Al_0.05O₂The mass percentage of the lithium-containing thin-layer coating material relative to the basic anode material is 0.03 wt%.

Example 3

Step 1: A200L kneader is selected, stirring is started (30rpm), and 100kg of nickel-cobalt-aluminum precursor (Ni) is added under the stirring condition_0.81Co_0.16Al_0.03(OH)₂) Then 58.8kg of lithium oxalate powder is weighed and added into a kneader, 0.64kg of aluminum isopropoxide (the aluminum content is about 800ppm based on the finished product) is added under the stirring condition, and after 1 hour of stirring, the speed is further reduced (10rpm) for stirring for 30min, and the paste material is formed for standby.

A24 m ventilated roller kiln is adopted. Setting the temperature of the heating zone at 750 deg.C, and introducing oxygen-enriched air (oxygen content volume ratio of 70%, gas input of 600 Nm)³And h) putting the paste material into a ceramic sagger for sintering, wherein the sintering time is 8h, isolating the material from air, cooling to normal temperature, weighing the weight of the material in and out, and counting the loss on ignition to be 29.1%. Then crushing by a cyclone vortex crusher with a protective gas nitrogen source, controlling the humidity of air circulation nitrogen to be less than or equal to 2% during crushing, and obtaining a semi-finished product sintered for the first time, wherein the granularity (D) of the material_v50) 16.0 μm, specific surfaceProduct of 2.5m²And/g, namely the basic cathode material.

Step 2: and adding the semi-finished product into the kneader again, adding 0.88kg of nano titanium dioxide dispersion (ceramic grade, titanium content is about 1000ppm according to finished product), fully dispersing, taking out the powder, filling the powder into a ceramic sagger, and adopting a 24m ventilated roller kiln. Setting the temperature of the heating zone to 880 ℃, and introducing oxygen-enriched air (the volume ratio of oxygen content is 90%, and the gas input is 350 Nm)³And h) filling the first sintering semi-finished powder into a ceramic bowl for sintering, wherein the sintering time is 8h, cooling the materials to normal temperature in an air-isolated mode, weighing the weight of the materials in and out, and counting the loss on ignition to be 5.1%. Then crushing by a cyclone vortex crusher with a protective gas nitrogen source, controlling the humidity of air circulation nitrogen within 2 percent during crushing, namely coating a titanium-containing lithium compound layer on the surface of a basic anode material to finally obtain the nickel-cobalt lithium aluminate anode material with the granularity (D)_v50) 8.5 μm, a specific surface area of 1.47m²/g。

The ICP is used for carrying out quantitative analysis on the elements of the nickel cobalt lithium aluminate anode material, and the structural formula is as follows: li_1.02Ni_0.81Co_0.16Al_0.03O₂The mass percentage of the lithium-containing thin-layer coating material relative to the basic positive electrode material is 0.07 wt%.

Example 4

Step 1: A500L ceramic ball mill is selected. Starting stirring (30rpm, weight ratio of polyurethane ball material to raw material 1.3:1), adding 100kg of nickel-cobalt-aluminum precursor (Ni) under stirring_0.82Co_0.17Al_0.01(OH)₂) And then 47.8kg of monohydrate lithium hydroxide powder is weighed and added into a ceramic ball mill, 16.2kg of deionized water and 0.25kg of lithium metatitanate (the content of titanium is 1000ppm based on the finished product) are added under the condition of stirring, the speed is further reduced (10rpm) after the stirring is carried out for 2 hours, the stirring is carried out for 4 hours, and polyurethane spheres are filtered out to form paste materials for later use.

A24 m ventilated roller kiln is adopted. Setting the temperature of the heating zone at 800 deg.C, and introducing oxygen-enriched air (oxygen content volume ratio of 70%, gas input of 600 Nm)³H) filling the paste-like material into a ceramic saggerSintering for 8h, isolating the materials, cooling the materials to normal temperature in an air-cooling mode, weighing the weight of the materials in and out, and counting the loss on ignition to be 35.3%. Particle size of the Material (D)_v50) 6.0 μm, a specific surface area of 0.61m²And/g, obtaining a first sintering semi-finished product, namely the basic anode material.

Step 2: and adding the semi-finished product into a ceramic ball mill again, adding 0.14kg of nano magnesium oxide (ceramic grade, the magnesium content is about 800ppm in terms of the finished product), fully dispersing, taking out the powder, filling the powder into a ceramic sagger, and adopting a 24m ventilated roller kiln. Setting the temperature of the heating zone to 840 ℃, and introducing oxygen-enriched air (the volume ratio of oxygen content is 70%, the gas input is 400Nm³And h) filling the first sintering semi-finished powder into a ceramic bowl for sintering, wherein the sintering time is 8h, cooling the materials to normal temperature in an air-isolated mode, weighing the weight of the materials in and out, and counting the loss on ignition to be 5.1%. Then crushing by a cyclone vortex crusher with a protective gas nitrogen source, controlling the humidity of air circulation nitrogen within 2% or less during crushing, namely coating a magnesium-containing lithium compound layer on the surface of the basic anode material to finally obtain the nickel-cobalt lithium aluminate anode material with the granularity (D)_v50) 7.5 μm, a specific surface area of 1.29m²/g。

The ICP is used for carrying out quantitative analysis on the elements of the nickel cobalt lithium aluminate anode material, and the structural formula is as follows: li_1.02Ni_0.82Co_0.17Al_0.01O₂The mass percentage of the lithium-containing thin-layer coating material relative to the basic anode material is 0.01 wt%.

Example 5

Step 1: A200L coulter type mixer is selected, stirring is started (the rotating speed of a main shaft is 130rpm, the rotating speed of a side cutter is 1400rpm, the stirring time is 50min), and 100kg of nickel-cobalt-aluminum precursor (Ni) is added under the stirring condition_0.80Co_0.15Al_0.05(OH)₂) Then 27.7kg of lithium hydroxide powder is weighed and added into a coulter type mixer, 38kg of deionized water and 0.29kg of lithium metaaluminate (the content of aluminum is 1100ppm based on the finished product) are added according to the solid content of 80 wt% under the condition of stirring, the speed is further reduced (the rotating speed of a main shaft is 100rpm, the rotating speed of a side cutter is 1400rpm) after 2 hours of stirring, and the mixture is stirred for 4 hours to obtain the lithium hydroxide powderThe materials are formed into paste materials for standby.

A24 m ventilated roller kiln is adopted. Setting the temperature of the heating zone at 400 ℃, introducing oxygen-enriched air (the volume ratio of oxygen content is 45 percent), and the gas input quantity is 400Nm³And h) putting the paste material into a ceramic sagger for primary sintering, wherein the sintering time is 13h, isolating the material from air, cooling to normal temperature, weighing the weight of the material in and out, and counting the loss on ignition to 39.1%. And then crushing by using a cyclone vortex crusher with a protective gas nitrogen source, wherein the humidity of the protective gas nitrogen source is controlled to be less than or equal to 2% during crushing, and a first sintered semi-finished product, namely the basic anode material, is obtained.

Step 2: and adding the semi-finished product into a coulter type mixer again, adding 0.17kg of lithium titanate (battery grade, the titanium content is about 800ppm according to the finished product) and 0.37kg of magnesium acetate (the magnesium content is about 600ppm according to the finished product) into the mixer, fully dispersing (the rotating speed of a main shaft is 120rpm, the rotating speed of a side cutter is 1500rpm, and stirring time is 40min), taking out the powder, filling the powder into a sagger, and adopting a ventilated 24m roller kiln. Setting the temperature of the heating zone at 700 deg.C, and introducing oxygen-enriched air (oxygen content volume ratio is 80%, gas input is 400Nm³And h) putting the semi-finished product of the first sintering into a ceramic sagger for second sintering, wherein the sintering time is 8h, isolating the materials from air, cooling to normal temperature, weighing the weight of the materials in and out, and counting the loss on ignition to be 5.6%. Then crushing by a cyclone vortex crusher with a protective gas nitrogen source, controlling the humidity of air circulation nitrogen within 2 percent during crushing, namely coating a layer of lithium compound containing titanium and magnesium on the surface of a basic anode material to finally obtain the nickel-cobalt lithium aluminate anode material with the granularity (D)_v50) 13.0 μm, a specific surface area of 1.52m²/g。

The ICP is used for carrying out quantitative analysis on the elements of the nickel cobalt lithium aluminate anode material, and the structural formula is as follows: li_1.05Ni_0.80Co_0.15Al_0.05O₂The mass percentage of the lithium-containing thin-layer coating material relative to the basic positive electrode material is 0.05 wt%.

Example 6

Step 1: selecting a 200LY type mixer, starting stirring (35rpm), adding while stirring100kg of nickel-cobalt-aluminum precursor (Ni) was added_0.80Co_0.15Al_0.05(OH)₂) Then 42.9kg of lithium carbonate powder is weighed and added into a mixer, 20kg of deionized water and 0.22kg of nano cobaltous hydroxide (the cobalt content is 1300ppm based on the finished product) are added according to the solid content of 90 wt% under the stirring condition, the speed is further reduced (3-5 revolutions per minute) after the stirring is carried out for 2 hours, and the material is discharged to form a paste material for later use.

A24 m ventilated roller kiln is adopted. Setting the temperature of the heating zone at 500 deg.C, introducing oxygen-enriched air (oxygen content volume ratio is 45%, gas input amount is 200Nm³And h) putting the paste material into a ceramic sagger for primary sintering for 15h, cooling the material to normal temperature in an air-isolated mode, weighing the weight of the material in and out, and counting the loss on ignition to be 32.1%. Then crushing by a cyclone vortex crusher with a protective gas nitrogen source, and controlling the humidity of the circulating nitrogen to be less than or equal to 2% during crushing to obtain a first sintered semi-finished product, namely the basic anode material.

Step 2: adding the semi-finished product into a Y-shaped mixer again, adding 0.24kg of nano aluminum hydroxide (ceramic grade, the aluminum content is about 800ppm based on the finished product), fully dispersing 0.03kg of lithium hydroxide monohydrate, taking out the powder, filling the powder into a ceramic sagger, and adopting a 24m ventilation roller kiln. Setting the temperature of the heating zone at 700 deg.C, and introducing oxygen-enriched air (oxygen content volume ratio is 70%, gas input amount is 600 Nm)³And h) putting the semi-finished product of the first sintering into a ceramic bowl for second sintering, wherein the sintering time is 8h, cooling the materials to normal temperature in an air-isolated mode, weighing the weight of the materials in and out, and counting the loss on ignition to be 2.9%. Then crushing by a cyclone vortex crusher with a protective gas nitrogen source, controlling the humidity of air circulation nitrogen within 2 percent during crushing, namely coating an aluminum-containing lithium compound layer on the surface of a basic anode material to finally obtain the nickel-cobalt lithium aluminate anode material with the granularity (D)_v50) 10.0 μm, a specific surface area of 0.32m²/g。

The ICP is used for quantitatively analyzing elements of the nickel cobalt lithium aluminate anode material, and the structural formula is as follows: li_1.02Ni_0.80Co_0.15Al_0.05O₂The mass percentage of the lithium-containing thin-layer coating material relative to the basic positive electrode material is 0.25 wt%.

Example 7

Taking a commercial finished product (Li)_1.02Ni_0.80Co_0.15Al_0.05O₂) About 100kg (equivalent to the basic anode material) of the powder was put into a coulter type mixer, 0.34g of lithium titanate (battery grade, titanium content about 1600ppm in terms of finished product) was added by dry mixing method, and the powder was taken out and put into a ceramic sagger after being fully dispersed (main shaft rotation speed 130rpm, side cutter rotation speed 1400rpm, stirring time 40min), and a vented 24m roller kiln was used. Setting the temperature of the heating zone at 700 deg.C, and introducing oxygen-enriched air (oxygen content volume ratio is 80%, gas input is 500Nm³And h) putting the semi-finished product of the first sintering into a ceramic bowl for second sintering, wherein the sintering time is 8h, cooling the materials to normal temperature in an air-isolated mode, weighing the weight of the materials in and out, and counting the loss on ignition to be 5.6%. Then crushing by a cyclone vortex crusher with a protective gas nitrogen source, controlling the humidity of air circulation nitrogen within 2 percent during crushing, namely coating a titanium-containing lithium compound layer on the surface of a basic anode material to finally obtain the nickel-cobalt lithium aluminate anode material with the granularity (D)_v50) 10.0 μm, a specific surface area of 1.63m²/g。

The ICP is used for carrying out quantitative analysis on the elements of the nickel cobalt lithium aluminate anode material, and the structural formula is as follows: li_1.02Ni_0.80Co_0.15Al_0.05O₂The mass percentage of the lithium-containing thin-layer coating material relative to the basic anode material is 0.03 percent.

Comparative example 1

Comparative example 1 is the same as step 1 of example 1 of the present invention except that nano titanium dioxide, yttrium nitrate hexahydrate and magnesium acetate added thereto were removed in step 2.

Particle size of the Material (D)_v50) 9.4 μm, a specific surface area of 2.3m²(ii) in terms of/g. The ICP is used for carrying out quantitative analysis on the elements of the nickel cobalt lithium aluminate anode material, and the structural formula is as follows: li_0.99Ni_0.81Co_0.15Al_0.05O₂。

Comparative example 2

Comparative example 2 is the same as step 1 of inventive example 5 except that lithium titanate and magnesium acetate added thereto were eliminated in step 2.

Particle size of the Material (D)_v50) 8.3 μm, a specific surface area of 2.92m²(ii) in terms of/g. The ICP is used for carrying out quantitative analysis on the elements of the nickel cobalt lithium aluminate anode material, and the structural formula is as follows: li_1.01Ni_0.81Co_0.15Al_0.05O₂。

Comparative example 3

Comparative example 3 is the same as step 1 of inventive example 6 except that the nano aluminum hydroxide and lithium hydroxide monohydrate components added thereto are eliminated in step 2.

Particle size of the Material (D)_v50) 8.5 μm, a specific surface area of 1.94m²(ii) in terms of/g. The ICP is used for carrying out quantitative analysis on the elements of the nickel cobalt lithium aluminate anode material, and the structural formula is as follows: li_1.02Ni_0.81Co_0.16Al_0.03O₂。

Application example 1 SEM image

The powder of the nickel cobalt lithium aluminate positive electrode material prepared in the above example 5 and comparative example 2 was subjected to SEM test by scanning electron microscope to obtain the results shown in fig. 1-a and 1-b, respectively. FIG. 1-a is a SEM image of example 5, and FIG. 1-b is a SEM image of comparative example 2. The EDS tests were carried out simultaneously for example 5 and comparative example 2, and the test results are shown in Table 3.

Table 3 EDS test results table

As can be seen from table 3, the nickel cobalt lithium aluminate cathode material of example 5 has obviously detected the existence of magnesium and titanium elements, and as can be seen from fig. 1-a and fig. 1-b, the particle surface of comparative example 2 is smooth, and the surface of example 5 has a coating layer in the form of tiny particles, and the coating layer is uniformly attached to the surface of the material and is fused with the bulk of the material, and the size of the particles is measured in nanometers. As can be seen from the results of table 3 and fig. 1-a and 1-b, in the examples, a layer of material is uniformly coated on the surface of the lithium nickel cobalt aluminate positive electrode material by coating with magnesium and titanium elements.

Application example 2 full cell preparation and Performance evaluation

The 4 positive electrode material powders prepared in example 1, example 6, comparative example 1 and comparative example 3 are used as positive electrode active materials to prepare power batteries with the capacity of 4.5-4.8Ah according to the 21700 cylindrical battery design, and the cylindrical batteries have the same tolerance as the standard in the design (namely, the volume occupied by the active materials in the cylindrical batteries is about 96 percent of the total closed effective volume of the cylindrical batteries). The full cell is manufactured and mainly used for inspecting high voltage circulation and safety effects. The variety evaluated to be suitable is a 21700 steel shell battery with a winding structure, and the diameter of the manufactured battery is 21mm, and the height of the manufactured battery is 70 mm.

The positive pole piece is prepared by preparing slurry, coating, cold pressing, slitting and the like, the content of the effective positive active substance in the pole piece is 97.5 percent, and the average coating weight of the pole piece is 0.0260g/cm³The coating width of the pole piece is 62mm, and the total area of the active substances of the pole piece is 937.4cm²The thickness of the aluminum foil base material is 13 mu m, and the compacted density of the pole piece is 3.2g/cm calculated by active substances³。

The preparation method of the negative plate is generally prepared by the steps of preparing slurry, coating, cold pressing, slitting and the like. When the artificial graphite is used as the negative active material, the content of the prepared pole piece effective negative active material (artificial graphite) is 96.0 percent, and the coating weight of the pole piece is 0.0164g/cm²The coating width of the pole piece is 63.5mm, and the total area of the active substances of the pole piece is 1009.65cm²The thickness of the copper foil base material is 9 mu m, and the compacted density of the pole piece is 1.65g/cm calculated by active substances³。

The method comprises the steps of sequentially winding a positive plate welded with an aluminum tab, an isolation film (a PP/PE/PP composite isolation film processed by nano aluminum oxide and having the thickness of 16 mu m), a negative plate welded with a nickel tab and the like to prepare a cylindrical bare cell, sleeving the tab on an insulating ring, putting the tab into a shell, welding the nickel tab at the bottom of a cylinder by laser welding, then preparing the bare cell with a groove by curling, drying, cooling, injecting liquid, sequentially welding protective members such as CID and PTC on the tab, packaging, standing, and forming by a high-temperature forming machine of an LIP-10AHB06 type (forming voltage of 0-4.2V, charging of 0.1C and discharging of 0.2C at the temperature of 45 +/-2 ℃), carrying out capacity testing (testing voltage of 3.0-4.2V, 0.2C and 0.5C), and selecting qualified cells for subsequent performance evaluation.

The lithium batteries prepared in example 1, example 6, comparative example 1 and comparative example 3 were placed in an oven at 60 ℃, and the electrodes were connected to a high temperature forming machine of the LIP-10AHB06 type for 0.5C/0.5C, 3.0-4.2V cycle testing, resulting in the high temperature cycle results of FIG. 2.

As can be seen from FIG. 2, the cycle performance of the cylindrical battery prepared in the example is greatly improved compared with that of the cylindrical battery prepared in the comparative example, the cycle of the comparative example 1 is rapidly reduced and then is stably attenuated, and the battery of the comparative example 3 is directly jumped. The lithium-containing thin-layer coating material is coated on the surface of the basic positive electrode material, so that the cycle performance, particularly the high-temperature cycle performance, of the nickel-cobalt-aluminum material is improved.

In order to detect the dissolution condition of the structural elements of the positive electrode material in the lithium ion battery in use, the effect and the mechanism of the invention are discussed, after the lithium batteries prepared in examples 1, 6, 1 and 3 are cycled for 200 times at 60 ℃ at 0.5C/0.5C, the cycled examples and lithium ion batteries are discharged to 3.0V at 0.01C on a testing machine, then the lithium batteries are disassembled in a glove box and taken out of a negative electrode plate, the negative electrode plate is cleaned by using a solvent DMC (dimethyl carbonate) and then dried, then part of the active material of the negative electrode plate is scraped, the content of the nickel, cobalt and aluminum element deposits in the negative electrode plate is tested by adopting ICP, and meanwhile, the negative electrode plate is compared with the negative electrode plate for the lithium ion battery before preparation, and the result in the table 4 is obtained.

Table 4 detection results of element content of lithium ion battery negative electrode plate after circulation of examples and comparative examples

As can be seen from table 4, the content of the metal elements of nickel, cobalt, and aluminum in the negative electrode sheets of the lithium ion batteries of examples and the lithium ion batteries of comparative examples increases before and after the cycle, but the metal ion elution effect of the lithium ion batteries of examples is much weaker than that of the comparative group, and the content does not increase after the content increases to 800 ppm. The nickel-cobalt lithium aluminate anode material prepared by the invention effectively inhibits the dissolution of structural metal elements such as nickel, cobalt and aluminum in the anode material.

Application example 3 safety Performance test results

Nailing (nail diameter phi 8mm, piercing speed 20-25 mm/s) the 21700 type cylindrical lithium ion secondary battery prepared by the positive electrode material prepared in the embodiment 1, the embodiment 6, the comparative example 1 and the comparative example 3 according to QC/T743-, the cells were then left to stand for 2 hours for standard testing, yielding the results shown in fig. 3 and table 5.

TABLE 5 results of nail penetration test

As can be seen from fig. 3, the lithium batteries prepared in example 1 and comparative example 1 of the present invention both passed the nail prick abuse condition and the temperature rise was not obvious, but the internal resistance of the lithium battery cell prepared in comparative example 3 increased sharply after the internal resistance test, and the conditions for use as a reversible lithium ion battery were actually lost, and the resistance and weight of the battery were not measurable. Thus, it can be derived: besides poor cycle performance, the lithium ion battery without surface treatment also has larger safety risk in the use process of the cathode material without the surface-coated lithium-containing thin layer coating material, which shows that the nickel-cobalt-aluminum cathode material prepared by the method of the invention effectively controls the dissolution of structural metal elements of the nickel-cobalt-aluminum cathode material by adopting a method of coating a lithium compound, and meanwhile, the transitional lithium-containing compound coating room effectively relieves the dangerous reaction of the lithium ion battery under the abuse condition and improves the safety performance of the lithium ion battery.

In conclusion, the stable and uniform bulk lithium-containing thin-layer coating layer is formed on the surface of the nickel-cobalt lithium aluminate anode material, so that powder particles of the anode material are prevented from directly contacting with an electrolyte in the later use process, the dissolution of structural metal elements of the nickel-cobalt-aluminum anode material is inhibited, the use of the nickel-cobalt-aluminum anode material in a high-voltage and long-cycle system is facilitated, and the safety performance of a lithium battery is improved. The preparation method disclosed by the invention is economical and feasible, simple to operate, obvious in effect and good in application prospect.

While specific embodiments of the invention have been described with reference to the above examples, it will be understood by those skilled in the art that the foregoing examples are for purposes of illustration only and are not intended to limit the scope of the invention, which is to be construed as limiting the present invention.

Claims

1. The preparation method of the nickel cobalt lithium aluminate anode material is characterized by comprising the following steps of:

step 1: mixing a nickel-cobalt-aluminum precursor, a lithium source compound and an auxiliary agent, and performing heat treatment to obtain a basic positive electrode material;

step 2: mixing the basic anode material with the unreacted lithium source compound and the IIA, IIIA, IIIB, VIB and VIII group metal compounds in the step 1, and performing heat treatment to obtain a nickel-cobalt lithium aluminate anode material, wherein the nickel-cobalt lithium aluminate anode material comprises the basic anode material and a lithium-containing coating thin layer coated on the surface of the basic anode material;

wherein, the auxiliary agent in the step 1 is one or more than two of ester, salt or hydroxide containing lithium, magnesium, titanium, cobalt, yttrium, zirconium, cerium and aluminum;

the group IIA, IIIA, IIIB, VIB and VIII metal compounds in the step 2 are selected from one or more than two of oxides, salts or hydroxides of magnesium, titanium, cobalt and yttrium;

the mass percentage of the auxiliary agent relative to the total mass of the nickel-cobalt-aluminum precursor and the lithium source compound is 0.03-0.6 wt%;

the nickel cobalt lithium aluminate anode material comprises a basic anode material and a lithium-containing coating thin layer coated on the surface of the basic anode material, and the chemical formula of the nickel cobalt lithium aluminate anode material is Li_xNi_aCo_bAl_cO₂Wherein: x is more than or equal to 0.98 and less than or equal to 1.02, a is more than or equal to 0.80 and less than or equal to 0.82, b is more than or equal to 0.15 and less than or equal to 0.17, c is more than or equal to 0.01 and less than or equal to 0.05, and a + b + c = 1.0-1.03;

the specific surface area of the nickel cobalt lithium aluminate anode material is 0.3-1.7m²/g；

The mass percentage of the lithium-containing coating thin layer relative to the basic anode material is 0.01-0.50 wt%;

the lithium-containing coating thin layer is selected from a lithium compound layer containing one or more than two of magnesium, titanium, aluminum and yttrium;

the mass percentage of the unreacted lithium source compound in the step 1 in the step 2 relative to the mass percentage of the lithium source compound in the step 1 is 0.09-0.55 wt%;

the temperature of the heat treatment in the step 1 is 400-800 ℃; the heat treatment time is 8-16 h;

the temperature of the heat treatment in the step 2 is 700-880 ℃; the heat treatment time is 8-10 h;

the mixing equipment in the step 1 and the step 2 is selected from one or more than two of a kneader, a fusion machine, a rake type mixer and a coulter type mixer;

the heat treatment equipment in the step 1 and the step 2 is a roller kiln.

2. The preparation method according to claim 1, wherein the particle size of the nickel cobalt lithium aluminate cathode material is 7-14 μm; the specific surface area of the nickel cobalt lithium aluminate anode material is 1.2-1.7m²/g。

3. The production method according to claim 1 or 2, wherein the lithium-containing clad thin layer is contained in an amount of 0.01wt% to 0.30wt% with respect to the mass of the base positive electrode material.

4. The method according to claim 1 or 2, wherein the precursor in step 1 is a hydroxide and/or an oxide containing nickel, cobalt and aluminum elements.

5. The preparation method according to claim 3, wherein the precursor in step 1 is hydroxide and/or oxide containing nickel, cobalt and aluminum elements.

6. The production method according to claim 1 or 2, wherein the lithium source compound in step 1 is one or more selected from lithium carbonate, lithium hydroxide monohydrate, lithium hydroxide, lithium acetate, lithium nitrate, lithium fluoride, lithium tert-butoxide, lithium citrate, and lithium oxalate.

7. The production method according to claim 3, wherein the lithium source compound in step 1 is one or more selected from lithium carbonate, lithium hydroxide monohydrate, lithium hydroxide, lithium acetate, lithium nitrate, lithium fluoride, lithium tert-butoxide, lithium citrate, and lithium oxalate.

8. The production method according to claim 4, wherein the lithium source compound in step 1 is one or more selected from lithium carbonate, lithium hydroxide monohydrate, lithium hydroxide, lithium acetate, lithium nitrate, lithium fluoride, lithium tert-butoxide, lithium citrate, and lithium oxalate.

9. The production method according to claim 5, wherein the lithium source compound in step 1 is one or more selected from lithium carbonate, lithium hydroxide monohydrate, lithium hydroxide, lithium acetate, lithium nitrate, lithium fluoride, lithium tert-butoxide, lithium citrate, and lithium oxalate.

10. The production method according to claim 1 or 2, wherein the content of the unreacted lithium source compound in step 1 in step 2 is 0.1wt% to 0.4wt% with respect to the mass of the lithium source compound in step 1.

11. The production method according to claim 3, wherein the content of the unreacted lithium source compound in the step 1 in the step 2 is 0.1wt% to 0.4wt% with respect to the mass of the lithium source compound in the step 1.

12. The production method according to claim 4, wherein the content of the unreacted lithium source compound in the step 1 in the step 2 is 0.1wt% to 0.4wt% with respect to the mass of the lithium source compound in the step 1.

13. The production method according to claim 5, wherein the content of the unreacted lithium source compound in the step 1 in the step 2 is 0.1wt% to 0.4wt% with respect to the mass of the lithium source compound in the step 1.

14. The production method according to claim 6, wherein the content of the unreacted lithium source compound in the step 1 in the step 2 is 0.1wt% to 0.4wt% with respect to the mass of the lithium source compound in the step 1.

15. The method according to claim 7, wherein the content of the unreacted lithium source compound in the step 1 in the step 2 is 0.1wt% to 0.4wt% with respect to the mass of the lithium source compound in the step 1.

16. The method according to claim 8, wherein the content of the unreacted lithium source compound in the step 1 in the step 2 is 0.1wt% to 0.4wt% with respect to the mass of the lithium source compound in the step 1.

17. The method according to claim 9, wherein the content of the unreacted lithium source compound in the step 1 in the step 2 is 0.1wt% to 0.4wt% with respect to the mass of the lithium source compound in the step 1.

18. The production method according to claim 1, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere, and the oxygen content by volume is 40-95%; air flow rate of 200-600Nm³/h。

19. The production method according to claim 2, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere, and the oxygen content by volume is 40-95%; air flow rate of 200-600Nm³/h。

20. The production method according to claim 3, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere having an oxygen content of 40 to 95% by volume; air flow rate of 200-600Nm³/h。

21. The production method according to claim 4, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere, and the oxygen content by volume is 40-95%; air flow rate of 200-600Nm³/h。

22. The production method according to claim 5, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere, and the oxygen content by volume is 40-95%; air flow rate of 200-600Nm³/h。

23. The production method according to claim 6, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere, and the oxygen content by volume is 40-95%; air flow rate of 200-600Nm³/h。

24. The production method according to claim 7, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere, and the oxygen content by volume is 40-95%; air flow rate of 200-600Nm³/h。

25. The production method according to claim 8, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere, and oxygen is used as oxygenThe gas volume content is 40-95%; air flow rate of 200-600Nm³/h。

26. The production method according to claim 9, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere having an oxygen content of 40 to 95% by volume; air flow rate of 200-600Nm³/h。

27. The production method according to claim 10, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere having an oxygen content of 40 to 95% by volume; air flow rate of 200-600Nm³/h。

28. The production method according to claim 11, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere having an oxygen content of 40 to 95% by volume; air flow rate of 200-600Nm³/h。

29. The production method according to claim 12, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere having an oxygen content of 40 to 95% by volume; air flow rate of 200-600Nm³/h。

30. The production method according to claim 13, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere having an oxygen content of 40 to 95% by volume; air flow rate of 200-600Nm³/h。

31. The production method according to claim 14, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere having an oxygen content of 40 to 95% by volume; air flow rate of 200-600Nm³/h。

32. The production method according to claim 15, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere, and the oxygen content by volume is 40-95%; air flow rate of 200-600Nm³/h。

33. The method of claim 16The method comprises the following steps of (1) carrying out heat treatment in an oxygen-enriched atmosphere, wherein the volume content of oxygen is 40-95%; air flow rate of 200-600Nm³/h。

34. The production method according to claim 17, wherein the atmosphere of the heat treatment in step 1 is an oxygen-rich atmosphere having an oxygen content of 40 to 95% by volume; air flow rate of 200-600Nm³/h。

35. The production method according to claim 1 or 2, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere having an oxygen content of 45 to 70% by volume; air flow rate of 200-400Nm³/h。

36. The production method according to claim 3, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere having an oxygen content of 45 to 70% by volume; air flow rate of 200-400Nm³/h。

37. The production method according to claim 4, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere, and the oxygen content by volume is 45-70%; air flow rate of 200-400Nm³/h。

38. The production method according to claim 5, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere having an oxygen content of 45 to 70% by volume; air flow rate of 200-400Nm³/h。

39. The production method according to claim 6, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere, and the oxygen content by volume is 45-70%; air flow rate of 200-400Nm³/h。

40. The production method according to claim 7, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere, and the oxygen content by volume is 45-70%; air flow rate of 200-400Nm³/h。

41. The production method according to claim 8, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere, and the oxygen content by volume is 45-70%; air flow rate of 200-400Nm³/h。

42. The production method according to claim 9, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere having an oxygen content of 45 to 70% by volume; air flow rate of 200-400Nm³/h。

43. The production method according to claim 10, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere having an oxygen content of 45 to 70% by volume; air flow rate of 200-400Nm³/h。

44. The production method according to claim 11, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere having an oxygen content of 45 to 70% by volume; air flow rate of 200-400Nm³/h。

45. The production method according to claim 12, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere having an oxygen content of 45 to 70% by volume; air flow rate of 200-400Nm³/h。

46. The production method according to claim 13, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere having an oxygen content of 45 to 70% by volume; air flow rate of 200-400Nm³/h。

47. The production method according to claim 14, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere having an oxygen content of 45 to 70% by volume; air flow rate of 200-400Nm³/h。

48. The production method according to claim 15, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere, and the oxygen content by volume is 45-70%; air flow rate of 200-400Nm³/h。

49. The production method according to claim 16, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere having an oxygen content of 45 to 70% by volume; air flow rate of 200-400Nm³/h。

50. The production method according to claim 17, wherein the atmosphere of the heat treatment in the step 1 is an oxygen-rich atmosphere having an oxygen content of 45 to 70% by volume; air flow rate of 200-400Nm³/h。

51. The production method according to claim 1 or 2, wherein the atmosphere of the heat treatment in step 2 is an oxygen-rich atmosphere having an oxygen content of 60 to 95% by volume; air flow rate of 300-600Nm³/h。

52. The production method according to claim 3, wherein the atmosphere of the heat treatment in the step 2 is an oxygen-rich atmosphere having an oxygen content of 60 to 95% by volume; air flow rate of 300-600Nm³/h。

53. The production method according to claim 4, wherein the atmosphere of the heat treatment in the step 2 is an oxygen-rich atmosphere having an oxygen content of 60 to 95% by volume; air flow rate of 300-600Nm³/h。

54. The production method according to claim 6, wherein the atmosphere of the heat treatment in the step 2 is an oxygen-rich atmosphere having an oxygen content of 60 to 95% by volume; air flow rate of 300-600Nm³/h。

55. The production method according to claim 10, wherein the atmosphere of the heat treatment in step 2 is an oxygen-rich atmosphere having an oxygen content of 60 to 95% by volume; air flow rate of 300-600Nm³/h。

56. The method according to claim 18, wherein the atmosphere of the heat treatment in the step 2 is an oxygen-rich atmosphere having an oxygen content by volume60 to 95 percent; air flow rate of 300-600Nm³/h。

57. The method according to claim 35, wherein the atmosphere of the heat treatment in step 2 is an oxygen-rich atmosphere having an oxygen content of 60 to 95% by volume; air flow rate of 300-600Nm³/h。

58. The production method according to claim 1 or 2, wherein the atmosphere of the heat treatment in step 2 is an oxygen-rich atmosphere having an oxygen content of 70 to 90% by volume; air flow rate of 350-600Nm³/h。

59. The production method according to claim 3, wherein the atmosphere of the heat treatment in the step 2 is an oxygen-rich atmosphere having an oxygen content of 70 to 90% by volume; air flow rate of 350-600Nm³/h。

60. The production method according to claim 4, wherein the atmosphere of the heat treatment in the step 2 is an oxygen-rich atmosphere having an oxygen content of 70 to 90% by volume; air flow rate of 350-600Nm³/h。

61. The production method according to claim 6, wherein the atmosphere of the heat treatment in the step 2 is an oxygen-rich atmosphere having an oxygen content of 70 to 90% by volume; air flow rate of 350-600Nm³/h。

62. The production method according to claim 10, wherein the atmosphere of the heat treatment in the step 2 is an oxygen-rich atmosphere having an oxygen content of 70 to 90% by volume; air flow rate of 350-600Nm³/h。

63. The production method according to claim 18, wherein the atmosphere of the heat treatment in the step 2 is an oxygen-rich atmosphere having an oxygen content of 70 to 90% by volume; air flow rate of 350-600Nm³/h。

64. The production method according to claim 35, wherein the atmosphere of the heat treatment in the step 2 is an oxygen-rich atmosphereThe oxygen volume content is 70-90%; air flow rate of 350-600Nm³/h。

65. A lithium ion battery positive electrode material, which is prepared by the preparation method of any one of claims 1 to 64.

66. A positive electrode for a lithium ion battery, which is produced from the positive electrode material according to claim 65 and an aluminum foil.

67. A lithium ion battery comprising the positive electrode material according to claim 65 or the positive electrode according to claim 66.

68. The lithium ion battery of claim 67, wherein the battery reversible capacity retention and/or recovery capacity is greater than 85% after high temperature cycling testing.

69. The lithium ion battery of claim 67, wherein the battery reversible capacity retention and/or recovery capacity is greater than 90% after high temperature cycling.

70. Use of the positive electrode material of any one of claims 1 to 64 or the positive electrode of the lithium ion battery of claim 66 or the lithium ion battery of any one of claims 67 to 69 in the field of lithium electrical energy.